What is Normalization in SQL ?

Normalization is used to decompose a larger, complex table into simple and smaller ones. This helps us in removing all the redundant data.

Generally, in a table, we will have a lot of redundant information which is not required, so it is better to divide this complex table into multiple smaller tables which contains only unique information.

First normal form:

A relation schema is in 1NF, if and only if :

– All attributes in the relation are atomic(indivisible value)

– And there are no repeating elements or group of elements.

Second normal form:

A relation is said to be in 2NF, if and only if:

It is in 1^st Normal Form.

No partial dependency exists between non-key attributes and key attributes.

Third Normal form:

• A relation R is said to be in 3NF if and only if:

It is in 2NF.

No transitive dependency exists between non-key attributes and key attributes through another non-key attribute